Sesame Street Elmo Cookie Monster Happy Birthday Party Balloons Decorations. Elmo & Cookie Monster Happy Birthday Party Balloons Decorations. (1) HUGE 38" Waving Elmo mylar shape balloon. (1) 31" Cookie Monster Foil Mylar. (2) 18"Sesame Street Happy Birthday Foil Balloon, (1) 18" Sesame Street Gang Non Message (6) Polka Latex Balloons. Colors as Shown.